Some 4.567 billion years ago, our Solar System’s planets spawned from an expansive disk of gas and dust rotating around the Sun. While similar processes are witnessed in younger solar systems throughout the Milky Way, the formative stages of our own Solar System were believed to have taken twice as long to occur. Now, [continue reading]

Comets and asteroids preserve the building blocks of our Solar System and should help explain its origin. But there are unsolved puzzles. For example, how did icy comets obtain particles that formed at high temperatures, and how did these refractory particles acquire rims with different compositions? Carnegie’s theoretical astrophysicist Alan Boss and cosmochemist Conel [continue reading]